condusco: Query-Driven Pipeline Execution and Query Templates

Runs a function iteratively over each row of either a dataframe
or the results of a query. Use the 'BigQuery' and 'DBI' wrappers to
iteratively pass each row of query results to a function. If a field
contains a 'JSON' string, it will be converted to an object. This is
helpful for queries that return 'JSON' strings that represent objects.
These fields can then be treated as objects by the pipeline.